Persons having problems emptying their bladders often use catheters to aid urination. Furthermore, it is common today to use an intermittent catheter, which the user can operate by him/herself without the need for assistance from a second person and only when voiding of the bladder is needed. Thus, the need of permanent catheterisation is avoided and more freedom and quality of life is obtained for the user.
A typical intermittent catheter comprises a tubular body having a proximal end, which is initially inserted into the urethra and a distal end opposite the proximal end. At least one opening at the proximal end is in fluid connection with an opening at the distal end. The opening at the distal end is usually coaxially connected to a so-called connector. A connector is generally a conical shaped tubular body tapering outwardly from the distal end of the catheter. The connector may be used to connect the catheter to an extension tube or a urine bag and a user can use the connector to operate the catheter. By holding the connector only the user may guide the catheter into the urethra, thereby avoiding touching the catheter body and thus reducing the risk of contaminating the tubular body.
In use, the user will typically grab hold of the connector and guide the catheter body into the urethra, starting by inserting the proximal end. When the opening at the proximal end enters the bladder, urine will flow into the proximal end through the tubular body and out through the connector.
To reduce the risk of injuring the mucosa, the wall of the urinary channel, it is common to close off and round the proximal end of the tubular body, giving it a smooth tip which is gentle on the mucosa. Inlet openings, i.e. the openings at the proximal end, are instead provided on the side of the tubular body as so-called catheter eyes or eyelets. Such eyelets can be provided in different ways for example they can be cut, drilled, stamped out or molded together with the catheter when the catheter is produced by molding. Although the location of such eyelets reduces the risk of tearing the mucosa considerably, there is still need for improvement as the mucosa is very vulnerable and the edge of the eyelet and irregularities surrounding the eyelet might cause injury to the mucosa.
U.S. Pat. No. 3,149,186 discloses a method from making an improved catheter for peritoneal dialysis. The distal end of the catheter is provided with seventy to one hundred fifty small holes, having diameters ranging between 0.010 to 0.025 inches. The holes are punched by heated pins, where the temperature of the pins is adjusted to a point where they soften, but do not melt, the wall of the thermoplastic tubing. In this way, the plastic material displaced by the pin is pushed inwardly forming an indented outer surface and an inner collar or flange.
GB patent 1 580 924 discloses a method especially applicable to the forming of lateral holes in plastics tubing of small diameter. The method comprises the steps of piercing the wall of the cannula with a needle to form an aperture therein, withdrawing the needle from the aperture, driving the needle to rotate at high speed about its longitudinal axis, inserting the rotating needle in the aperture to contact the rim of the aperture as to cause frictional heating and consequently flow of material of the workpiece and thereby smooth out the rim contour.